HIV Linked to Lower Scores on Children's Intelligence Tests

July 2011—Children who were infected with HIV at birth have been shown to have a higher risk of delays in various aspects of their development due to the damage HIV can cause to the brain. A study conducted in Chiang Mai, Thailand, focused on evaluating the cognitive functioning of children with HIV by looking at their performance on an intelligence test.1

(Photo: Louis V. Galdieri)

The study assessed three groups of Thai children 6-12 years of age: 39 with HIV, 40 who were exposed to HIV (their mothers were HIV-positive but they were not), and 42 neither infected nor exposed to HIV. Of the children with HIV, 87 percent had already been started on antiretroviral therapy.

The Thai researchers gave the children in this study an intelligence test that was modified and translated for use in Thailand, based on the Full Scale Intelligence Quotient (of the Wechsler Intelligence Scale for Children Version III). An average score of 90–109 on this test is considered to reflect an "average intelligence" level. Intelligence test scores are not designed to determine how bright children are or to assess their potential for learning, but they are an indicator of how children may perform in school settings.

In the first assessment, administered six months after enrollment in the study, the Thai children with HIV had lower test scores (average score of 79) than HIV-exposed but uninfected children (average score of 88) and unexposed children (average score of 96). Although 76 percent of children who were not exposed to HIV scored at the level of "average intelligence," only 21 percent of children with HIV scored at that level. In a second assessment, administered 30 months later, all children scored lower on their speaking and reading questions. It is important to note that family income was lower among those with or exposed to HIV, as were parents' and caregivers' age and education levels.

The researchers noted that the poor test scores among children with HIV could be the result of multiple factors, including the effect of HIV infection on brain development during the first few years of life, the socioeconomic status of the family, and the lack of parental care for orphans. By receiving the HIV diagnosis and starting treatment in infancy, children with HIV have a better chance of avoiding the risks of developmental delay.